AST: Remove OpenedArchetypeType::getSelfInterfaceTypeFromContext()

Author: slavapestov

include/swift/AST/Types.h

@@ -6785,15 +6785,6 @@ class OpenedArchetypeType final : public LocalArchetypeType,
          ArrayRef<ProtocolDecl *> conformsTo, Type superclass,
          LayoutConstraint layout);
 
-public:
-  /// Compute the parameter that serves as the \c Self type for an opened
-  /// archetype from the given outer generic signature.
-  ///
-  /// This type is a generic parameter one level deeper
-  /// than the deepest generic context depth.
-  static Type getSelfInterfaceTypeFromContext(GenericSignature parentSig,
-                                              ASTContext &ctx);
-
 public:
   /// Get or create an archetype that represents the opened type
   /// of an existential value.

lib/AST/ASTContext.cpp

@@ -6137,13 +6137,6 @@ CanGenericSignature ASTContext::getSingleGenericParameterSignature() const {
   return canonicalSig;
 }
 
-Type OpenedArchetypeType::getSelfInterfaceTypeFromContext(GenericSignature parentSig,
-                                                          ASTContext &ctx) {
-  return GenericTypeParamType::get(/*isParameterPack=*/ false,
-                                   parentSig.getNextDepth(), /*index=*/ 0,
-                                   ctx);
-}
-
 CanGenericSignature
 ASTContext::getOpenedExistentialSignature(Type type, GenericSignature parentSig) {
   assert(type->isExistentialType());
@@ -6206,7 +6199,7 @@ ASTContext::getOpenedExistentialSignature(Type type) {
 
   // Stash the `Self` type.
   existentialSig.SelfType =
-      OpenedArchetypeType::getSelfInterfaceTypeFromContext(parentSig, *this)
+      existentialSig.OpenedSig.getGenericParams().back()
           ->getCanonicalType();
 
   // Cache the result.